The peak and end rule, affect-related cognitions, enjoyment, and exercise frequency: A randomized controlled trial ancillary study.

Objective: Contemporary research has highlighted the important role of affect, affect-related cognitions (e.g., remembered/anticipated affect), and enjoyment for exercise adherence. The peak-and-end rule postulates that the affective peaks and end encountered during an episode of experience influence how pleasant/unpleasant the episode is remembered. This study aimed to explore the influence of these specific moments on affect-related cognitions, enjoyment, and exercise frequency.

Method: This study was based on a randomized controlled trial with two parallel groups. Forty-six non-regular exercisers (M = 32.00 years; SD = 8.62; 43.5 % male) were randomly allocated. Both groups participated in three exercise sessions structured according to the Frequency-Intensity-Time-Type (FITT) principle. However, in the experimental group, participants were encouraged to regulate their intensity using strategies theorized to promote pleasure. The Feeling Scale (FS) was used to measure affective responses. Linear regression analyses were applied to test the ability of FS peaks and FS end, in addition to the FS mean, FS slope, and FS start to predict remembered affect, next-session anticipated affect, enjoyment, and post-intervention exercise frequency (first week and the average of 8-week follow-up).

Results: All FS variables, except for the FS slope, meaningfully predicted remembered/anticipated affect and enjoyment (10 %-47 % explained variance). Regarding post-intervention exercise frequency, both affect-related cognitions and enjoyment exhibited significant predictive power (7 %-20 % explained variance).

Conclusion: The results corroborate the relevance of the peak and end rule and the value of affect-related cognitions and enjoyment for exercise adherence. Future studies should further test these concepts in longer interventions and follow-up periods.